a) steam turbo-alternators have long speeds b) steam turbo-alternators run at higher speed c) steam turbo-alternators are built with smaller capacities d) none of these Ans: (b)
a) the poles b) armature c) brushes d) none of these Ans: (a)
a) reverse the connection of its field winding b) interchange any two of its phase terminals c) both (a) and (b) d) none of these Ans: (c)
a) ɭ = D/2 b) ɭ = D c) ɭ = 2D d) ɭ >> D Ans: (d)
a) zero lagging b) zero leading c) unity d) more than unity Ans: (b)
a) to reduce the size of the machine b) to reduce the stray losses c) to reduce harmonic output d) to reduce accurate phase shift of 120° between each phase Ans: (c)
a) thermocouple method b) thermometer method c) by measuring the increase in winding resistances d) none of these Ans: (a)
a) economy of material used in winding b) reduction of irregularities produced in waveform c) less weight of the entire armature d) increase of generated emf per phase Ans: (b)
a) high speed alternators b) low speed alternators c) lagging power factor of the load d) leading power factor of the load Ans: (d)
a) 0° b) 85° c) 120° d) 135° Ans: (b)